A. No, fractionated oils are not the same as hydrogenated oils. In fact, they do not contain trans fats and are a healthier alternative to hydrogenated oils. But they are not perfect. Hydrogenation adds hydrogen to liquid vegetable oil to make a more solid oil with a longer shelf life. The downside is that the process creates trans fats, which raise total and LDL ("bad") cholesterol, lower HDL ("good") cholesterol, and contribute to obesity and diabetes. Trans fats turned out to be so nasty, that as of January of this year the U.S. Food and Drug Administration requires all food manufacturers to disclose whether foods contain any trans fats. Manufacturers are now scrambling to remove all trans fats so consumers will continue to buy their products. This is where fractionated oils come in.

Fractionated oils are increasingly used in place of unhealthful hydrogenated oils. In the fractionation process, vegetable oil is separated (often by a heating and cooling process) into different parts, with the more saturated (and thus more solid) part of the oil being used as a substitute for hydrogenated oils. Unlike hydrogenation, fractionation does not change the chemical structure of the oil and create trans fats. However, fractionated oils have a high percentage of saturated fats, which raise overall cholesterol levels and should be limited in the diet.

Smart fish oils for kidsQ. Should my child be taking fish oil supplements? Which are the best for children?

A. Fish contain omega-3 fatty acids crucial to brain and vision development. Unfortunately, many fish are contaminated by the toxic metal mercury—which can result in developmental delays and learning disabilities in children—so the U.S. Environmental Protection Agency recommends kids eat no more than two servings per week. By contrast, many fish oil supplements have been independently tested to ensure purity, so they can be a great way to get omega-3s without risking exposure to toxins.

Any child can benefit from fish oil supplements, which support cognitive development and immune function and lower the risk of diabetes. In addition, fish oil supplements have been shown in studies to help children with asthma, eczema, allergies, attention deficit hyperactivity disorder, behavioral and learning difficulties, and inflammatory bowel disease.

Perhaps the best supplements for kids are the liquid fish oil products, available in fruit flavors that taste surprisingly unfishy. Give these to your child by the spoonful, or if using a plain-flavored oil, pour over steamed vegetables (follow the label for age-appropriate doses). The liquid oil can also be added to a smoothie. However, avoid heating or using fish oil in hot foods, because doing so will destroy the omega-3 essential fatty acids. If a child is still breast-feeding, mom can take fish oil herself to increase the omega-3s conveyed through breast milk.

Ask the Expert was written by Victoria Dolby Toews, MPH, author of The Soy Sensation (McGraw-Hill, 2002) and The Green Tea Book (Avery, 1998).